Handle database timeouts from Khepri minority #10915
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The prior code skirted transactions because the filter function might cause Khepri to call itself. We want to use the same idea as the old code - get all queues, filter them, then delete them - but we want to perform the deletion in a transaction and fail the transaction if any queues changed since we read them. This fixes a bug - that the call to `delete_in_khepri/2` could return an error tuple that would be improperly recognized as `Deletions` - but should also make deleting transient queues atomic and fast. Each call to `delete_in_khepri/2` needed to wait on Ra to replicate because the deletion is an individual command sent from one process. Performing all deletions at once means we only need to wait for one command to be replicated across the cluster. We also bubble up any errors to delete now rather than storing them as deletions. This fixes a crash that occurs on node down when Khepri is in a minority.
The clause of the spec that allowed passing a list of queue name resources is out of date: the guard prevents a list from ever matching.
Previously a failing transaction would go unnoticed. Now we return an error tuple.
`khepri_tx:abort/1` is only meant for use within a transaction - I assume this was a relic of implementing this function with a transaction previously. The only caller already wraps this function in a `try`/`catch` block that logs the error and re-raises.
All callers assume that this operation will succeed.
This function is only used by the test suites. A backtrace should make the thrown error clearer though.
Note that we don't refactor the `throw/1` to an `erlang:error/1` since it's caught by `rabbit_vhost:add/3`.
This function is only used by a test suite which matches on the 'ok' return.
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These changes have been split out into other smaller PRs now |
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Operations like declaring/deleting queues fail when sent against a node that's part of a minority. We need to let the database failures (
{error, timeout}) bubble up to the callers - usually the channel - so that these operations don't cause needless crash reports.Closes #10753
This depends on a change upstream in Khepri: rabbitmq/khepri#256